Order Quantities

NOw this is the question that often throws me.  Factories want to know what your production quantity will be once you have finished sampling with them BUT my question is HOW do I know. Firstly I need orders but to get orders I have to have the samples complete. Maybe I have done this wrong...I should have gone to a sampling unit to get my styles sampled up after which I would go to stores to show and get an idea of orders and THEN contacted the factories to see if they can remake the sample ..mmmmhh actually that could work against me. I know i really need to seek funding as i want to have the money to actually produce to the quantities. I am saying 1-200 pieces each for now but not sure if that is enough or not....this fashion business game is not easy